Turning angle indicator



July 24, 1951 l. FRAZEE 2,562,142

TURNING ANGLE INDICATOR Filed Aug. 14, 1947 3 Sheets-Sheet 1 iii 1 INVENTOR iRWNG FRAZEE ATTORNEYS y 24, 1951 l. FRAZEE 2,562,142

TURNING ANGLE INDICATOR S=She etS-Sheet 2 Filed Aug. 14, 1947 INVENTOR IRVING FRAZEE 2 75 FIE; Q: NA BYG 0W ATTORNEYS July 24, 1951 1. FRAZEE 2,562,142

TURNING ANGLE INDICATOR 5 Sheets-Sheet 5;

Filed Aug. 14, 1947 I2 I 7o mveufoa mvme FRAZEE ATTORNEYS Patented July 24, 1951 UNITED STATES PATENT OFFICE TURNING ANGLE INDICATOR. Irving Frazee, Detroit, Mich;

Application August 14, 1947, SerialNo. 768,652

14 Claims. (Cl. 33203.18)

This-invention relates" to the art of aligning 'dirigible vehicle'wheels such as the front wheels ofan automobile and is particularly concerned with the provision of an improved" form of turning angle'indicator adapted to facilitate the positioning of 'such'wheels at desired turning angles for testpurposes;

' In testing a dirigible vehicle wheel to determine the presence and degree of such alignment characteristics as castertandking pin inclination, it is a conventional practice 'to turn the wheel suc- "fcessivelyto"selected angularsettings on opposite Sides ofstraight ahead position and to deterinlne" the desired alignment characteristics "by gauging certain differences inyattitude of the wheel at "these settings.

" ln'those cases where the alignment gauging apparatus is employed in conjunction with a turntable or other wheel support; the proper angular setting of the wheel is generally accomplished by reference to a suitable turning "scale or'sighting lines provided on the turntable'or other, portions oftthe supporting structure. In some instances, however, particularly when certain types of portable alignment gauges are used, itis sometimes desired to carry out the tests without any special wheel support other than the floor of the garage'or other place where the vehicle may happen to be standingv atthe time; and where no fixed reference means are present to enable accurate setting of the wheel to the proper angles.

It is the general object of my invention to provide a-turning angle indicator which'can' be used under thelatter circumstances to enable an operator to set the wheel to the proper angle for testing.

More particularly'it'is an object of my invention' topro-vide a simple and effective turnin angle indicator which may be'applied to a dirigible' vehicle wheel and utilized for accurately setting the wheel to desired angular positions for testpurposes.

Another object'is to provide a turning angle indicator of the character referred to which may e used with various makes and types. of wheel mountingshaving different radii of swing relative to their king pin assemblies.

Other objects and advantages of the invention will become more apparent from the following description of a preferred form of construction embodyingit, and the accompanying drawings wherein it is illustrated.

'{It'may be'pointed out herethat my invention may-be used entirely independently of any alignment gauging apparatuslf so-desired. Howeve since it is "expected; that it will generally be used in conjunction'with-some sort of gauging apparatus, it is believedthat its operation, advantages; and principal field of-utility will most readily be understood if so disclosed. I have,- therefore, illustrated and shall hereinafter describe 'my'invention as-it may beused in association with a well known make of alignment measuring gauge now on the market, it being understood that any one of various other gauges may be substituted for theone shownif desired; or it may be eliminated altogether. In the-drawings: Fig. 1 is a. perspective view of an automobile wheel having applied thereto a turning angle indicator embodyingmy invention and also a wheel alignment measuring gauge of the" character -re-'- ferred to above." 1 Fig. 2 is a perspectiveview of the turning angle indicator of Fig; 1 with the'wheel turned in one direction; while-Fig. 3 is a perspective view-of the same with the Wheel turned in an opposite direction;

Fig. 4 is an enlarged plan view of the wheel and attachment shown in Fig. l. N

Fig. 5 is-aside elevation, partially in section; of the assembly sh'ownin Fig. 1 andillustrating the turning "angle'indicator in a differentposi tion with respect to the wheel.

Fig. 6-is an end elevation, partially'insection, of the'assembly'shownin Fig; 5.

Fig; 7 is a section through the alignment meas-- uring gauge and turning angle indicator taken along line 1- of Fig.- 5i

Fig. 8 is adetail of the-crosshead forminga part of the turning angleindicatorof my invention; Fig. 9 is a side view of the cross head and at-'- tachments therefor.

Fig. 10 isa section through the hub portion-ofthe crosshead shown in Fig. 9 taken along line Ill-40 thereof.

' Fig. 11 is asection. through one extremity of Y stem of the T. Each extremity of the arm I5 is provided with a spacer block l8 adapted to rest against the outer face of the rim I9 of a wheel and having a screw stud 2| for engaging the periphery of the rim.

For the purpose of enabling the clamp |2 to be easily and quickly attached to the wheel 20, it is provided with a locking device slidably mounted on the two rods l6 and H. This looking device'is substantailly the same as the one shown in the aforementionedCarrigan application, except that it has been illustrated herein as being provided with a snugly fitting dust cover 26. Briefly, it comprises a body 21 carrying on its rear face a spacer block 28 similar to the blocks l8, and having a stud screw 29 for engaging the periphery of the rim [9. The slidable locking device 25 is normally adjusted to a position which permits the screw studs 2 I, 29 to be positioned over the periphery of the rim l9, as previously explained. The locking device 25 is controlled by a handle 30 which, when turned, actuates a spring urged clamp, not shown, for securing the locking device in position on the rods l6 and H. The screw studs 2| and 29 are thereby caused to cooperate with each other to clampingly engage the rim l9 of the wheel to supportthe clamp |2 firmly at one side of the rim.

Since the particular construction of the clamp l2 and its locking device 25 forms no part of my invention, it is believed that further description of these parts is unnecessary and reference is made to the aforesaid Carrigan application for additional details.

The bracket comprises a body of substantially rectangular form having aligned bosses 32 at each side thereof (Figs. 2, 3, and 6) each boss having openings bored lengthwise thereof for receiving the respective rods I6 and I1 whereby the, bracket is slidably supported by the rods for movement rectilinearly thereon. The back of the bracket II is provided with friction devices 33 (Fig. 6), each of which comprises a leaf spring 34, having one end secured to the back face of L the bracket and a detent 35 at its opposite end extending through an openingprovided in the bracket. The detents 35 bear against the respective rods l6 and I! to retain the bracket in adjusted position ,on the rods.

, The front face of the bracket H has a boss formation 36 thereon from which extends a shaft 31 adapted to pivotally support the gauging mechanism 10 so'that the latter will normally hang in a vertical position. The shaft 31 is preferably disposed coaxially with respect to the wheel by adjusting the bracket I along the rods l6 and I! as above explained.

The gauging apparatus l0 comprises a hollow casing 40 of generally rectangular cross section provided with aligned bores 4| and 42 in its vertical end walls, and similarly aligned bores 43 and 44 in its vertical side walls, the axis of the bores 4|,"42 being offset vertically relative to the axis of the bores 43, 44, as is shown in Figs. 5 and '6. The lower region of the casing 40 (Fig. 6) is also provided with aligned bores '45, 46 which are parallel to the bores 43, 44 for pivotally supporting pintles 48 extending laterally from a pendulum pointer 49. The portion 50 of the pendulum 49, below'the pintles 48,-is weighted so as to maintain the pointer portion 5|, thereabove, in vertical position. The pointer portion 5| is provided with an arcuate eye 52' in alignment with the aforementioned bores '43, 44, and a similar eye 53 4 is in alignment with the bores 4|, 42 to permit swinging movement of the pointer and casing relative to each other without interference from the shaft 37.

The upper end of the pointer portion 5| extends into a slot 55 in the upper end of the casing 40 to provide a needle pointer 55 associated with graduated scales 5! and 58 on either side of the slot 55 for indicating the angular tilt of the pendulum 49 relative to' the casing 4|. The scale 51 is a fixed scale calibrated to read in inches or degrees of camber while the scale 58 ils adjustable and calibrated to read in degrees of caster or king pin inclination. The adjustable scale 58 is in the form of an endless ribbon running over a pair of spaced rollers (not shown) within the upper portion of the casing 40, and

" adjustment of the scale is accomplished by turning a knob 59 fixed to a drive shaft on one of the rollers. This construction is illustrated in the aforesaid Carrigan application and reference is made thereto for further and more specific details.

When it is desired to make a check for. either camber or caster, the casing 40 is journalledo'n the shaft 31 with the latter extending through the upper bores 4|, 42, (Figs. 1 to 4) so that the pendulum 49 will swing in a plane normal to the plane in which the wheel 20 is disposed. 'The wheel is then placed in a plane parallel to the longitudinal axis of the vehicle, i. e., in straight ahead position. Since camber is the amount in inches or degrees that the front wheels are tilted outwardly at the top, it is only necessary to note the degrees indicated on the camber scale 51 by the needle 56 due to' tilting of the casing '40 with the shaft 37 while the needle remains in a vertical position.

, Caster is the amount in degrees that the king pin is tilted toward the rear of the vehicle. Starting with the parts in the position described immediately above, caster is determined by first turning the wheel in one direction to a predetermined angular position at one side of the straight ahead position, as shown in Fig. 2 and then turning the knob 59 to adjust the scale 58 to bring its zero graduation into registry with the pointer 55. The wheel is then turned to a core responding angular position at the opposite side of straight ahead position whereupon the resulting change in inclination of the wheel will cause the pointer 56 to indicate the degrees of caster angle on the scale 58.

King pin inclination is the term employed in a this art to identify the inclination of the king pin transversely of the vehicle. .When thi is to be ascertained, the casin 49 is removed from the shaft 31 and turned from the. position shown in Figs. 1 to 4 and is remounted on the shaft 31 with the latter extending through the-bores 43, 44 (Figs. 5 and 6) so that the pendulum will swing in a plane parallel to the plane in which the wheel 20 is disposed. The wheel is then turned to the same predetermined angle at one side of itsstraight ahead position as Was done in the caster test and the knob 59 is manipulated to ad-: just thev scale 58 to bring its zero graduation into registry with the pointer 56. For the remainder of this test it is necessary that the wheel be prevented'from rotating on its spindle and this may be accomplished by setting the vehicle brakes. It is also necessary to prevent the casing 4|] from swinging on it supporting shaft 31 and for this purpose the casing is provided with a thumb screw 60 i (Fig. '7) for securing the casing to the shaft.

Atithis time-therefore, thelvehicle brakes arelset and-"theathumb screw.fiflltighteneddown. .andthe wheellis. thenv turned :to the opposite. side of. its straight ahead. position thesame. aswa done in the caster. test.. It will now .be'ffound thatin so turning the wheel the casing 40 has been. tilted andlthe readingofthespointer on the. scale58=will indicate the amount in degrees that the kingpin isinclined transversely. of thevehicle.

It .will be. noted 1 that. in .makingeach ofthe abovezdescribedtests the angle .to which. the wheel isrturned .on onesideof :straight ahead position must be .thasamaasthe angle'to whichthe wheel isotllrned .onv .the opposite. side of straight ahead position, and, furthermore, these. angles must be the predetermined amountfor which the caster and king in inclination scale ofthe gauging ap- Daratusiscalibrated,-.otherwise the scale readings will be inaccurate- .qThe; present invention provides a simple attachment which may readily be appliedto the wheel to enable it to beset. in the proper angular positions referred to. This attachment (Figs. '7 to11.1 .inclusive) comprises acrosshead 6] having arhub portion Bland radial arms 63 and 64, each providedwith aring65 at its end,.. The rings 65 are recessed as shown at 66 (Figs. 8 and 11) toreceive a disc 61 from above. The disc 6! are each provided with an eccentric hole 68-and an eccentricdcpressionBS diametrically opposite eachothenand communicating with each other by way of, slot terminating at the center of the depression 69..

-.,..Associated with each of the arms. 63 and, is a plumb line 12 and 13, respectively, each having az-plumb .bob secured toits lower end as indicated at,.14. ,and 15. Each plumb line is preferably a singlestrand ball-type chain having its upper endpextending throughtheopening 63in the disc BLa dadapted to1slide throughthe slot ill to thejhub 62 of :the crosshead 61 is provided with-asocketlfi (Figs. 7,and .10) to'fit the end of the shaft-.131. The hub 62 .isgsecured to the shaft 3,! by va set screw ll in sucha manner that the plumb bobs are pendently supported in the manner shownin Fig.1.

-'..-A. geometrical. diagramof the present inventionisillustrated in connectionwiththe plan view thereof (Fig. 4)., wherein. the crosshead BI is shownin horizontal position and it is assumedthat it is desired. to turn the wheel to a position which is;. ,2.0 from thestraight ahead position thereof.

It;.will, therefore, be noted that the radius lines R -extending from the midpoint of the king pin Ktothe centers of the plumb lines 12,13 are disposedat angles of 10 fore and aft from the axis Asof the wheel 20,.it being understood that these: radius lines R lie in a. plane through the wheel axis A which plane is horizontal when the wheel chamber is zero. The crosshead. 6|, therefore from. one plumb line to the other, represent a chord line C based upon the arc of a 20=sector of' a circle having aradius R.

,Among. different makes and types of vehicles thesdistance from the king pinto the outer face of 'the wheel rim .varies somewhat according to manufacturers design, although the maximum variation amongpresentday vehicles isyonly ap. proximately three inches, Any variation inthis; distance, however, will, obviously, also. .vary the.

length of the radius R. as. welLas the chord line C, and. it. is, therefore, apparent that the. proper. dis-- tance between. the plumb lines, is .determinedby the. distance of the plumb linesfrom the midpoint of the kingpin and by theangle through which itis desired. to. turn the wheel from straight ahead position. v I l For purposes of illustration, it will be assumed that .onespecific manufacturer. puts outtrucks and passenger cars... The trucks, being heavier, havea front wheel swing which is two inches greater thanthat ofthe passenger cars. Such facts being known, the device of the present in-v vention when-applied. to a truck wheel would es:- tablish, for example, a radius. R of nineteen inches, and the passenger car wheel .a radius r of seventeen inches, from the king pinto the plumb lines of the angle indicator. Assuming that a radius .R of nineteen inches is the. maxi; mum for all vehicles known in the industry, they length of the crosshead 6| is such that when the. crosshead is disposed horizontally on the shaft 31. (Figs. 1 to l, inclusive) it will defineqa chord C (from plumb line to plumb line) based upon the arc of a 20 sector. of. a circle having a nineteen inch radius. Y Each plumb line 12 and 13 is adjusted'so that the plumb bob'carried. thereby hangs from the crosshead to just about touch the surface S upon which the, wheel 20 is resting. The surface S may be any suitable level, such as the floor of a-shop or test room, adapted to receive distinguishable markings, for example, two substantially parallel chalk lines 18 and 19 illustratedv in Figs. 1 to 4, inclusive. .The lines 18 and'l9 are drawn .upon the surface S substantially'normal to the plane of the wheel in its straight ahead position-to indicate the position of plumb bobs 14, 15 relative to the axis A when the wheel 20 is in straight ahead position (Figs. 1 and 4). I v

Consequently, whenv the wheel is turned clockwise to the dotted line position shown in Fig. 4' (full line position, Fig. 3) the plumb bob 15 will be disposed above the chalk line 18 and when pointing to thesame, will indicate that the wheel has been turned 20 from straight ahead position. The knob 59 is then turned to adjust the graduated .scale 58 .to bring its zero graduation into registry with the pointer 56. The wheel is then turned counterclockwise. until the lumb bob 14- is disposed above and pointing toward the chalk line 19, as is shown in Fig.2, indicating that the wheel is now positioned 20 counterclockwise from straight ahead position. The reading on the graduated scale 58 is then noted to ascertain the particular caster angle or king pin inclination; as hereinbefore stated.

In the case of checking a passenger car wheel= having a shorter than nineteen inch: radius from the king pin to the plumb lines (seventeen inches, for example), it is apparent that the chord line of a 20 sector of an are having such. a radius will be proportionately shorter than the chord line C of the previous example. Such a shorter radius is indicated at r in Fig. 4 and the short-- ened chord line at c. It is, therefore, necessary to adjust the distance between plumb'lines I2 and 13 to correspond to the length of the new chord line c andthis may be accomplished by rotating" the crosshead Bl about the shaft 31 so as totil-t the crossheadarms (Figs. 5 and 6) and'thusbring the plumbzlines into the proper spacing. 1

To facilitate accurate adjustment of Y the crosshead,.' as stated abo'venoneof the arms 63 thereof. -.is..provided with a depending fin 4 (Figsw 5 and-9) extending from the hub 62 to the end of the arm 63. The outer face of the fin 80 is provided with indicia 81, each of which is disposed radially relative to the center of the ball B seated in the depression 69 of the disc 61 associated with the arm 63, The indicia Bl are angularly spaced relative to each other in the fashion of a protractor and are read in conjunction with the position of the plumb line 12 relative to the arm 63. In the specific instance herein recited, the angular disposition of the crosshead would be 26 32 from normal or horizontal position in order to space the plumb bobs from each other a distance equal to a chord c for a 20 sector of a circle having a seventeen inch radius r.

Consequently, the set screw 1! is released and the crosshead 6| swung clockwise (Fig. 5), until the plumb line 12 hangs in alignment with indicia No. 3 which is 26 32 from indicia No. 0. The set screw 11 is again tightened to secure the crosshead 6| in fixed relation with respect to the shaft 31.

The indicia 8| on the face of the fin 80 are arranged to indicate the degree of tilt of the crosshead to suit any one of the various makes and types of automotive vehicles. Each of the indicia is identified by a key number which may be posted on a chart having information printed thereon as to the make and type of car and the angle to which the crosshead must be tilted in order to indicate a 20 turn of the wheel of a particular car.

With the crosshead tilted, as aforesaid, it is necessary to readjust the length of the plumb lines 12, 13 by sliding each ball chain laterally in the respective slot so as to permit lengthening of the chain on one arm and a corresponding shortening of the chain on the opposite arm of the crosshead so that both plumb weights 14, 15 will be disposed just above the surface S. Each chain '12, 13 is again slid through the slot 70 to seat one ball thereof on the depression 69 in the corresponding disc 67. Thereafter, two parallel chalk lines 18 and I9 are drawn upon the surface S with the wheel in straight ahead position. The same procedure as stated above in connection with Figs. 2 and 3 is then followed whereby the turning of the wheel into 20 inward and outward positions facilitates the calculation of caster angle and king pin inclination of the passenger car wheel.

Once the plumb lines are spaced a proper distance horizontally from each other in the manner explained above, any visual mark, such as chalk lines on a surface adjacent the plumb bobs will suffice to indicate the straight ahead position of the wheel. When the wheel is turned either direction until one plumb bob registers with the visual mark at the normal position of the other plumb bob, the proper turning angle of the wheel will be attained.

I have pointed out hereinabove that my invention is not limited to use with the particular gauging apparatus illustrated but may be used with other types of gauging apparatus as Well, or independently of any gauging apparatus at all.

It will also be understood that in describing my invention as it may be used for determining a wheel turning angle of 20 to each side of straight ahead position, this particular angle has been selected only for purposes of illustration and any other turning angle may be selected instead simply by varying the distance between the slots 10 to correspond to the desired angle. Other modifications and alterations may also be made in the design, construction, or use of my inven*. tion without departing from the spirit or scope. thereof and I, therefore, desire to avail myself of all such modifications, alterations, variations, and uses as come within the purview of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. Apparatus for indicating similar angles ofturn of a member turnable about a substantially upright axis in either direction from an initial position, comprising an arm mounted on said member in laterally offset relation to such axis, and with the ends of said arm disposed substantially equidistant from a given point on saidaxis, and a plumb bob suspended from each end of said arm, each plumb bob being adapted to cooperate with visual marks made on a horizontal.

surface supporting said member to locate the position of said plumb bobs when said member is in its initial position whereby to indicate that said member is disposed a similar angle of turn to one or the other side of said initial position:

when said member is turned into a position in which either of said plumb bobs registers with the mark which was made on said surface adjacent the other plumb bob when the member wasin its initial position.

2. Apparatus for indicating the angle of turn. of a dirigible wheel about a king pin, comprising an arm mounted on and parallel with the face of said wheel and offset a predetermined distance laterally from said king pin, and a pair of plumb bobs suspended from said arm in predetermined spaced relation so as to be disposed substantially equidistant fore and aft of the hub axis of said wheel, said plumb bobs being adapted to 00-- located at the position of the other plumb bob when the wheel was in straight ahead position. 3. A turning angle indicator for use with apparatus for checking the caster and king pin inclination of the king pin of a dirigible vehicle wheel, comprising a support mounted on said dirigible wheel substantially in axial alignment with the spindle about which it rotates, an arm mounted midway its ends on said support for tilting movement in a plane parallel to the face of said Wheel, and a plumb bob pendently sup-- ported at each end of said arm adapted to cooperate with visual marks made on the wheel supporting surface in registration with the plumb bobs when the wheel is in straight ahead posi-' tion for indicating that said wheel is disposed ata similar angle of turn either inwardly .or outwardly from said straight ahead position when said wheel is turned in either direction from straight ahead position until one plumb bob registers with the mark which was made on said wheel supporting surface adjacent the other plumb bob.

4. A turning angle indicator for use with apparatus for checking the caster and king pin inclination of the king pin of a dirigible vehicle Wheel, comprising a rod mounted on said wheel substantially in axial alignment with the spindle of said dirigible wheel, an arm mounted mid-' way its ends on said rod for tilting movement in a plane parallel to the face of said wheel, a plumb bobincluding alt-{plumb line pendentlyffsupported at each end of said aim; means for -securing said arm in a" predetermined position of tilt onsaid for 'spacing the plumb bobs 'a' pred'e'termined distance from feach' other 'dependent-fupon} the angleit is desired to turn said wheetfiand means for-lengthening or shortening said plumblinesfso that-said plumbbobs are adapted tobooperate with "visual 'marks' made opposite the Same or'i the wheel supporting surface when the wheel is in straight ahead-*' position to indicate'-that{said wheel is disposed fatthe desired--angle-' 'of turn from said straight ahead position {when the wheel is turned into a position in which either plumb bob registers witli'the'visual marklocated, during straight ahead position of thewh'eel', o'p'- posite the other'plumb bob. 5. Apparatus foriind-icating a desiredangie-or turn'of a dirigible wheel" about a kingpin, com prising an arm moun'ted on said wheel for tilt: ing movement in a plane parallel' to the fface or said wheel and aboutfan'axi's'substantially 'in alignment with the spindle of said *dirigible wheel, a; pair of pl'u'mbli'ns carryin'g plu'mb bobs pendently supported from said "arm diametrically opposite each other with respect tothefaxis of tilting movement of said arm;,means'for maintaining said arm in;'tilt e'd" position for varying thefs'pacing of said jplumb bob-s -with respect to each other in 'accordance with the desired angle of turn, and means for adjusting the length "of the plumb-lines of said plumb bobs for disposing the'latter adjacent the wheel supporting surface whereby said'plumb bobs will cooperate with visual marks located'on the wheel supporting surface to indicate" the-position of said plumb bobs when the wheel is in straight -ahead-'posi non so that when the wheel isturne'dtherefrom until one of saidplumb bobs registers'with the visual mark'indicating thepo'sition assumed by the other plumb bob duringstraight ahead position' of the wheel, the wheel will be*disposed' at the desired angle of turn'relative to said'straight ahead position of the wheel.

6.'Apparatus for indicating a desired angle of turn of a dirigiblewheel ab outa king pin, comprising an armsupported foradjustment into different positions of ti-lt aboutan axis sub'stantially coinciding with the spindle of said wheel for varying the spacing between a pair ofplumb bobs depending from said arm, a pair of plumb bobs havingtheir plumb lines pendently supported on said arm-diametrically opposite each other with respect to'theaxis about which'said armjis tiltable, means-on saidarm'coope'rating with one'of said plumb lines for indicating the angle of tilt of said arm relative to horizontal, and thereby the spacing between said plumb bobs, the angle of tilt being dependent upon the distance of said arm from the king pin and the angle it is desired to turn said wheel, and means for changing the lengths of said plumb lines for disposing said plumb bobs adjacent a wheel supporting surface, said plumb bobs being adapted to cooperate with visual marks located on the wheel supporting surface indicating the position of said plumb bobs when the wheel is in straight ahead position, and for indicating that the desired angle of turn has been attained when the wheel has been turned into a position in which one of said plumb bobs coincides with the visual mark which indicated the position assumed by the other plumb bob when the wheel was in straight ahead position.

'7. A turning angle indicator for use with apparatus for checking the caster and king pin inclination of the king pin of a dirigible vehicle wheel, comprising a rod mounted on said wheel substantially in axial alignment with the spindle about which'thewheel rotates, an arm mounted midway its ends on said rod for tilting movement in'a'plane parallel to the face of said wheel, a pairof plumbbob's each having a plumb line pendently supported-"one from each end of said arm, means for"'securing said arm in a predetermined position of tilt on said'rod for spacing the plumb bobs a predetermined lateral distance from each other based upon the distance ofsaidarm from the king pin and the angle it is desired to turn said Wheel, and means for changing the length of-the plumblines of said plumb bobs for disposing the plumb bobs'adjacent a wheelsup porting surface whereby said plumb bobs will cooperate with visual marks located on said surface at the position of the plumb bobs when the wheel is in straight ahead position to thereby indicate thatthe wheel has been turned to the desired angle of turn when one of said plumb bobs substantially registers withthe visual mark which indicated the position assumed by the other plumb bob when the wheel'was in straight thead position.

8. Apparatus for indicating similar anglesof turn of a dirigible wheel about a king pinin either direction from straight ahead position, comprising an arm supported on said" wheel for tilting movement about: an axis which is substantially coaxial with the spindle of said-dirigible wheel, a pair of plum bobs each having a plumb line pend-- ently supported on said arm equidistant from the tilt axis of said arm and diametrically oppositeeach other relative to the same, said arm having a dial thereon cooperating with the plumb line of one of said plumb bobs: for indicating the desired tilt of the arm for spacing the plumb bobs from each other a distanceudetermined bythe distance of said-arm from the king pin and the angle it is desiredto turn said wheehand means for maintaining said arm in the desired tiltedpoe sition, said, plumb bobs :being; adapted to cooperate'with marks located on-a wheel supporting surface at the positiqnlof said plumb bobs relative to said supporting surface'when the wheel is in straight ahead position-forsubsequently indicating ,that the proper turning angle of said wheel has been attainedwhen the wheel has been turned until one of said plumb bobs substantially coincides with the mark located on the wheel supporting surface at the position assumedby theotl erplumb, bob when the wheel was in straightiahead position. a 9. A turning anglerindicator for use -with,ap.-, paratus forclieckingg-theycaster and king pin inclination of the king pin of a dirigible vehiele wheel, comprising a bracket secured to said wheel for movement therewith, a shaft mounted on said bracket substantially in alignment with the spindle of said wheel, an arm mounted on said shaft for tilting movement, a pair of plumb bobs having plumb lines pendently supported on said arms substantially equidistant from said shaft and diametrically opposite each other with respect to said shaft, means for securing said arm in a predetermined tilted position relative to said shaft for spacing said plumb bobs from each other a distance determined by the angle it is desired to turn the wheel and the distance between said arm and the king pin, and means for changing the lengths of the plumb lines of said plumb bobs dependent upon the tilted position of said arm to dispose said plumb bobs adjacent the Wheel supporting surface for facilitating marking on -saidsurface the positions assumed by said plumb bobs when the wheel is in straight ahead position whereby when the wheel is turned into a position in which either plumb bob registers with the mark indicating marked position assumed by the opposite plumb bob during straight thead position of the wheel said wheel will be disposed at the desired angle of turn.

1,0. A turn indicator for a dirigible vehicle wheel rotatably mounted on a spindle to turn about a king pin as a pivot, the wheel being initially supported in straight ahead position on a horizontal supporting surface, the indicator comprising a plumb bob support adapted to be secured to said wheel in outwardly spaced relation thereto away from said king pin; a pair of plumb bobs mounted to depend from said plumb bob support at equal distances from the kingpin and in'ipredetermined separation from each other; the,

is turned to bring one of said plumb bobs'di-I 'rectly over a line on the supporting surface which 'line is: Substantially normal. to the plane 10f! the 1 wheel in -its"'strai'ghtahead position and .over which line the-otherplumb'bob was located in theistraight' ahead position of the wheel.

" 11;A' turn indicator for a dirigible vehiclewheel 'rot'atablyimounted 'on a spindle to turn at f.

12. An. arrangement as in claim 11 wherein an angle of tilt indicator is mounted adjacent one of said plumb bob-lines to be swept thereby on a pivotal movement of said plumb bob support, and angle marking indicia on said indicator adapted to align with said one plumb bob line in predetermined angle of tilt of the plumb bob support.

13. Apparatusv for indicating similar angles of turn of a member-turnable about -a substantially uprightaxis from an initial position comprising an arm-mounted 'O1'l said, member so that a line extendingtransversely from said axis at a given point thereonintersectsthe midpoint of said arm whereby the ends of said arm ar equidistant fromsaid, given point on said'axis, and a plumb bob suspended fromeach end-of said arm, each plumb bob beingadapted :to' cooperate with visual mar adeon;-a;horizontalsurface supportmg sa her to locates aid plumb bobs when said me is inits initialpositionwhereby' to indicate t said member is disposed ata-simi initial pos ion when said-member is turned into aposition inwhich either of said plumb-z bobs registers with the mark on said surface which was r comprisi gan-arm mounted-on said member so abouta kingpin a's'apivot; the wheel beingl i n'l-j tially' supportediin straight ahead position on' a hori'zontal supporting'surface, the indicator com prising af "plumb 'bob' support "adaptedto be mountedlior pivotal "adjustment substantial-1y co'-- axially-with said-wheel spindle and spaced out: wardly from said'wheel'along such common axis away-'fromfsaid king pin, a pair of plumb bobs mounted' to depend I from said plumb 'bob"sup-' port-in predetermined separation from each i other; means *f or'a'djusting the plumb bobs to the kingpin, thereby to indicate a predetermined angle-of turningmovement of the wheel about the kingpin lwherithe wheel is turned to bring one o'fsaid'plumb bobs directly over aline on the supporting surfac'whi'ch nae, i'S'substantiaIly normal to the plane of the iii/heel in itss traight ahead position and over which line the other plumb bob was located in the straight-aheadposn tion of the wheel.

that a ,linejxtending transversely from said-axis ata given point'thereon-intersects the midpoint of'said arm-whereby the ends of said arm are equidistant fromsaidgiven point on said axis, anda plumb bob suspended from each end of said armto locate visual-marks on a horizontal surface supporting said 'member when said member is in 'its yinitial position and adapted toindicate aaprede't Jnined'angle of turn whensaid mam d to place one plumb-bob adjacent ark which was adjacent the other said-member was in its initial 'IRVING'FR'AZEE.

.:I t Ei1 ERENCESCITED. v iThefol lowin'g' references are of record in the fileottliisriatrit: 1

- IEFSTATEsjPA Nf Ts Number "1 Name' Date 171,9? --Beckwith Jan. 11, 1876 649153 Gothan May-15, 1900 2,079,07

Johnston- May 4, 193'? urn'to one or the other side of said 

